1. Technical Field
The present invention relates generally to prepared peanut food products, and particularly to low calorie, low fat peanut products, such as peanut butter-like products, that are prepared and packaged either alone or in combination with jelly, jam, fruit spreads, conserves, marmalades and other similar preserves containing natural sugars or artificial sweeteners.
2. Related Art
Peanut butter is the eighth most popular food in the United States; it can be found in over 95 per cent of American homes. Its popularity is due to its unique mouth feel, the flavor of roast peanuts it delivers, and its excellent nutritional values.
The principal way that peanut butter is consumed is as a spread on bread or toast. Consumers often combine it with a preserve such as jelly, jam, fruit spread, conserve, marmalade, or similar high sugar-containing product. The flavor combination of roasted peanuts and fruit preserves is wonderful and is relished traditionally by children but also increasingly by adults.
There are a number of "peanut butter and jelly" type of products on the market, but their appeal is limited mainly to children. First of all, their flavor characteristic is primarily sweet, because the peanut flavor ranges from bland to almost nonexistent. Secondly, for weight-conscious adults, their high calorie, high fat content is a significant deterrent.
The flavor problem occurs because peanut butter is an oil-based system, commonly containing between 49% and 54% oil (natural peanut oil). It is well known in the peanut industry that water severely degrades the natural flavor elements of peanut butter, and peanut butter producers employ systems in their processes to insure the low moisture content of their products. Even the moisture absorbed over time in a partially consumed jar of peanut butter is enough to degrade the flavor, as every peanut butter lover is aware.
Preserves, such as jellies, jams, and fruit spreads, are all water-based products. When these products are blended with peanut butter, in time the water in the preserves will migrate into the peanut butter. Peanut protein exhibits a strong affinity for water. This property accounts for the familiar "sticky" mouth feel that consumers associate with peanut butter. The compounds that provide the roast peanut flavor in peanut butter are very sensitive to water, and the flavor will begin to change noticeably within hours after exposure to moisture. This condition intensifies with time; so that after only a few days of exposure, peanut butter that is in contact with water-based preserves has lost much of its roast peanut flavor notes and become bland.
While natural peanut butter is a generally healthful food, many nutritionists regard it as too rich in fats and calories. Peanut butter typically contains about 50% fat and has about 600 calories per 100 grams (or approximately 190 calories per 32 gram (two tbsps) serving). High fat content is an important factor in the rich taste and mouth feel of peanut butter, but it also renders normal peanut butter inadvisable for people who are calorie conscious, or who suffer from heart or artery disease.
Since preserves have little or no fat, combining peanut butter with a preserve can reduce the proportion of fat in the mixture. Although there is no critical range of proportions, consumers usually combine peanut butter with jelly, jam, or other fruit spreads in ratios ranging from about 2:1 to 4:1 (peanut butter to preserve) by weight. Even though the proportion of fat is reduced somewhat, this combination still constitutes a high calorie food.
Some work has been done to create low calorie, reduced fat whole peanut and peanut flour products. For example, the calorie content of whole peanuts has been reduced by partial removal of fats through a compression process, and low calorie, low fat peanut flours have been prepared by pressing and then milling either raw or roasted peanuts. As described in U.S. Pat. Nos. 3,947,599 and 4,113,889, these reduced fat content peanut flours have lost their peanut flavor characteristics and are very bland, almost tasteless. These patents propose using such flour as a base protein material for various food products, such as baked goods or protein extenders, but they do not suggest their use for low calorie, low fat peanut butter type products. The peanut flours described in these patents, in addition to having a bland taste, are generally dry, having water contents of under 5%.
The Agricultural Experiment Station of Auburn University has conducted extensive research into ways to use defatted peanuts in food products. In Bulletin 431 dated April 1972, entitled "Development and Use of Defatted Peanut Flours, Meals, and Grits," the acceptability of various food products made with defatted peanut flours is reported. In addition to breads, cakes, crisps, puddings, and ice creams, several peanut-honey spread recipes were tested. In none of these recipes did the weight of peanut flour exceed the weight of honey, and best results were obtained when the ratio of peanut flour to honey was 1:2. The score for flavor tests, however, was only 7.1 on a scale of 1 to 10. In retrospect, this is not so surprising; the amount of peanut flour would be too low to impart any peanut flavor even if it had any. The Bulletin listed on attempts to use defatted peanut flours to produce a low fat peanut butter, and, in fact, regular peanut butter was used in some peanut flour ice cream recipes to improve the flavor and texture.
More recently, Australian Patent Application No. 74497/87, published on Oct. 6, 1988 (corresponding to U.S. Pat. No. 4,828,868 issued to the present inventors on May 9, 1989), disclosed a low calorie peanut butter-like product and a process for making it from unroasted defatted peanut flour so that the resulting product has a desirable roast peanut flavor characteristic and a texture that nearly approximates that of generic peanut butter. There is no teaching in this document that a suitable peanut butter-like product could be made from roasted peanut flour or that a combination peanut butter-like and fruit preserve product could be provided that would maintain a desirable roast peanut flavor in the peanut component over a prolonged storage period.